Immunization against many viral diseases such as measles, mumps, and rubella occurs each year with little difficulty. The patient who has never had these diseases receives a vaccination, and this generates an antibody response similar to what a person experiences when he or she has that medical condition. In either case, receipt of the vaccine or acquisition of these diseases confers lifelong immunity for the individual.
Vaccines Against Other Diseases Mimic Natural Immunity
Though acquisition of these illnesses may yield better protective immunity than the vaccine, it is clear that the vaccine produces an immune response which is similar to the antibody response of the actual condition. In other words, vaccines in these instances mimic natural immunity.
With human immunodeficiency virus infection, however, the situation is different. First, people who acquire this disease do not generate much immune response. Second, the virus appears to undergo evolutionary changes in its outer envelope proteins. Though experimental vaccines against HIV do generate an immune response, the antibodies from that response do not always recognize the virus because of the alterations which have taken place.
Broadly Neutralizing Antibodies
Researchers have examined the possibility of an HIV vaccine that will induce broadly neutralizing antibodies. This is a challenge because very few patients who have this disease generate broadly neutralizing antibodies. The ones who naturally produce these antibodies have them one or two years after they acquire the infection. It may be that the person must experience long-term exposure to the virus before he or she will generate broadly neutralizing antibodies (Johnston and Fauci, 2011).
Some have suggested that long-term exposure to the virus is a requirement to induce broadly neutralizing antibodies because an evolutionary process generates B cells to yield antibodies which have considerable affinity for human immunodeficiency virus. This distinguishes the vaccine that appears to be necessary for HIV from vaccines against measles, mumps, and rubella as the HIV vaccine will not mimic natural immunity as those other well-known vaccines do.
Scientists have also examined broadly reactive cytotoxic T-cell responses against human immunodeficiency virus. Moreover, there have been experiments with nonhuman primates to develop the vaccine.
In any event, it is conceivable that a vaccine against human immunodeficiency virus will be necessary in order to eradicate the disease from the globe.
Sources
- Johnston, M. and Fauci, A. (2011). HIV vaccine development—Improving on natural immunity. New England Journal of Medicine, 365, 873-875.
- National Institute of Allergy and Infectious Diseases. (2011). HIV/AIDS. Vaccines. Retrieved September 14, 2011.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact their physician for advice.
Michael Koger - Dr. Koger obtained his medical education at Meharry Medical College and specialized in Internal Medicine.
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